A Northumberland Alpine Gardener's Diary
This entry: 04 December 2011 by John Richards
Northumberland Diary. Entry 199.
Remaking a small raised bed.
This is the time of year when I most often undertake major renovations in the garden. Plants are dormant and move readily, not resenting a few days out of the ground unless there is a hard frost. There is little else to do, and with the garden reduced to its skeletal winter bones it is easier to plan and to see 'the wood for the trees'. Leaf-mould and compost lies ready for use, and the ground is nicely moist without being waterlogged, so digging is easy and there is no fear of drought.
As intimated in the last entry (198), I have tackled several fairly small planting areas this autumn, removing perennial weeds, and, if necessary, plants which had become entangled with weed roots. New compost and/or leaf mould was added, plants divided and replanted, and if appropriate, the bed was top-dressed with grit or gravel. Some of the areas I have worked have been of long standing, and some have not really been touched since they were first constructed 20 or more years ago.
This was certainly true of a small raised bed which was in fact the first part of the rock garden terrace that I first built more than 21 years ago. In recent years it had become infested with red fescue from the lawn, as well as a multitude of other weeds, notably my bete noir, Vicia sepia (Bush Vetch). Apart from the invasive Sedum spurium no 'plants' had survived. This bed was once home to several saxifrages and a fine plant of their relative Luetkea pectinata, but no trace of these remained.
Unfortunately, I forgot to take a photo of the bed before work commenced, but once I had removed some rocks and scooped a thick skin of weeds from the top, I paused to make this record.
To put things in context, the conifer at the near end of the last photo is a Chamaecyparis obtusa 'Nana Aurea' which was one of the first plants I ever bought, 45 years ago, and the shrub at the far end is a Daphne alpina. The daphne in particular was infested with fescue and with Geranium macrorrhizum and I had to be very careful not to disturb the roots of this venerable daphne too much, while ensuring that it was freed of all weeds. Also, along the far side of the bed are several self-sown probably hybrid dieramas which have reappeared after nearly all dieramas were badly affected by last winters hard spell.
In order to make sure that all traces of weed roots had been removed, I had to dig out all the rocks, and these were lifted onto dumpy bags so they would not harm the grass too much.
Once the stones and all the weeds were removed, little remained of the original bed, except a low ridge of the original gravelly infilling. This was levelled to make the replacing of the stones easier.
The stones, which are a small fraction of the 10 tonnes of limestone we found here when we arrived, were then carefully repositioned to form the frame of the raised bed. Originally, they had been placed on their wider side, but to gain more height for the bed, they were replaced on their narrower edges. The bed no longer encompasses the daphne and is smaller than before, so that the three thinnest slabs of rock were not needed (or suitable) and were wheeled away and stowed for future reference.
As ou can see the new bed is really quite small, about 4 x 1 m, not much bigger than a large trough, and I intend to only grow small and potentially tricky subjects in it. It is small enough to be covered by a frame light in winter, and I may even construct a permanent framework for this next autumn, if it is not too unsightly.
Next, the bed was filled with sieved, well-rotted compost which was mixed with the stony brash which remained from its previous incarnation. I had bought four bags of a decorative gravel to top-dress the bed. At present this is a rather a bright colour, but I have every confidence from previous experience that the colour will tone down after a few months.
Here is the finished bed, and a picture of the bed in the context of the surrounding area. The daphne was been top-dressed with garden compost too which should help to mask the effects of any damage the roots may have suffered during operations.
There is very little in flower at the moment. Earlier this week I visited the Dorset Group near Wimborne, and I was very impressed by the number of beautiful plants that were displayed for their 'mini-show', including a wide range of lachenalias and other not very hardy South Africans. Apparently, these tender subjects are very popular in that area. Although they need supplementary heat in winter, very few if any would have survived last winter's freeze in north-eastern England in any conditions. Whether or not they are 'alpines' is contentious, but there is no doubting that they give one a lift at this time of year. From this display, and the Wisley website amongst other sources, it is clear that North-eastern growers are poorly provided with 'winter wonders' compared with our 'Friends from the South'.
Having said that, Cyclamen coum is flowering very early this year. Here is a group which is always early, growing under a tree. The flowers are poor, but it has lovely leaves.
The final picture is taken of part of the bench in one of the alpine houses, an area in which Igrow plants in the old sand plunge, rather than growing them in pots. In this photo are several strong plants of Primula kewensis, and a Primula grown from seed as P. rockii. I think the latter may prove to be P. bullata, another small relative of P. forrestii. Either way it is new to present-day cultivation, and I await flowering with bated breath!
Also in the above picture is Primula erratica on the left, a substantial plant of Saxifraga ferdinandi-coburgii, several small plants of Primula allionii, and a rather gappy Dionysia aretioides, one of three planted out like this which are largely trouble-free.